Magnetic configuration and timing scheme for transcranial magnetic stimulation

Abstract

Transcranial magnetic stimulation (TMS) is a remarkable tool for probing the brain. However, it is still unclear why specific regions in the cortex are excitable by TMS while others are not. This invention provides methods and tools for the design of efficient magnetic stimulators. Such stimulators can excite neuronal networks that were not sensitive to stimulation until now. Stimulation can be carried out both in-vitro and in-vivo. Novel systems and techniques of this invention will enable both treatment and diagnostics by stimulating regions of the brain or neuronal assemblies that were previously unaffected by TMS.

The invention claimed is: 
     
       1. A method for neuron excitation, wherein said neuron excitation comprises dendrite excitation, said method comprising:
 providing a device for dendrite excitation, said device comprising a capacitor connected to a coil and to a power supply, wherein the capacitance of said capacitor is at least 1.0 milliFarad; 
 subjecting a neuron to an electric field pulse longer than 250 μs in duration, induced by said device, wherein the strength of said electric field is at least 100V/m, thereby exciting said neuron. 
 
     
     
       2. The method of  claim 1 , wherein, said electric field pulse is equal to or longer than 1 ms in duration. 
     
     
       3. The method of  claim 1 , further comprising collecting or detecting an electric signal from said neuron. 
     
     
       4. The method of  claim 3 , wherein said collecting or detecting an electric signal from said neuron is done by Electroencephalography (EEG). 
     
     
       5. The method of  claim 1 , wherein said electric field is induced by a magnetic field, wherein said magnetic field is induced by passing current through a coil, wherein said coil is connected to a capacitor. 
     
     
       6. The method of  claim 1 , wherein said pulse duration exceeds the electric field duration threshold needed to excite a dendrite or a dendrite population. 
     
     
       7. A device for dendrite excitation, said device comprising a capacitor connected to a coil and to a power supply, wherein the capacitance of said capacitor is at least 1.0 milliFarad wherein said device generates an electric field pulse longer than 250 μs in duration wherein the strength of said electric field is at least 100V/m, thereby exciting said dendrite, and wherein said dendrite excitation causes a neuron to fire. 
     
     
       8. The device of  claim 7 , wherein said electric field pulse is equal to or longer than 1 ms in duration. 
     
     
       9. The device of  claim 7 , further comprising an electric signal detector or collector for collecting or detecting an electric signal from an excited neuron, wherein said detector or collector is an Electroencephalography (EEG) detector. 
     
     
       10. The device of  claim 7 , wherein said electric field is induced by a magnetic field, wherein said magnetic field is induced by passing current through a coil. 
     
     
       11. The device of  claim 7 , wherein said pulse duration exceeds the electric field duration threshold needed to excite a dendrite or a dendrite population.